JP2002159119A - Electrical junction box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an electrical junction box from being overheated and downsize it by the best layout of relays and fuses. SOLUTION: A hybrid printed circuit board with a conductor fixed on one surface and a bus bar fixed on the other surface is provided as an inner part circuit body of this electrical junction box. A heavy-current circuit serving as a power input is formed by the bus bar and mid- and small current circuits serving as outputs are formed by the conductor on the reverse surface side. Relay blocks with the relays mounted in a line are, at regular intervals provided in a plurality of rows on the bus bar mounting side, a fuse block with terminals connected to the fuses protrudingly attached in a line is provided between the relay blocks, and the bus bar is disposed between the relay block and the fuse block for regularly repeating its arrangement pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electric junction box,
In particular, the present invention is suitably used in an electric junction box that is mounted in an engine room of an automobile and supplies power, controls, and transmits and receives signals to electrical components mounted on the engine room side.

[0002]

2. Description of the Related Art Conventionally, in a motor vehicle, a large electric junction box composed of a junction box is arranged in a vehicle cabin, and the junction box is connected to electric components mounted on various parts of the vehicle via a wire harness, and a power circuit, The branch connection of the control circuit and the signal circuit is intensively performed. However, when electrical components mounted on the engine room side, such as head-side lamps and electronic control devices around the engine, are connected to the junction box on the indoor side, the wire amount of the wire harness increases and the configuration of the wire harness becomes complicated. There is a problem.

When it is necessary to connect a multiplex communication unit in an engine room to a display device in an instrument panel via a junction box, it is preferable to make a direct connection. For the reasons mentioned above,
Recently, various proposals have been made for mounting a junction box for an engine room in an engine room separately from a junction box mounted on the indoor side.

As shown in FIGS. 7 and 8, this type of engine room junction box has the same configuration as a junction box mounted on the indoor side. That is, the busbars 3 are stacked and housed in the case 1 via the insulating plate 2, and a fuse and a relay (not shown) are inserted into a housing portion provided in the case 1 to be connected to the busbar, and the upper cover is formed. 4 and a lower cover 5. Further, an electronic control unit such as an ECU is housed inside the case 1 at a part of an upper part or a lower part, or at one side, separately from the bus bar.

[0005]

However, the above-mentioned structure has a very complicated structure, and accordingly becomes larger and requires a large space for arrangement. Furthermore, if a circuit is formed only by bus bars formed by punching a conductive plate according to the circuit configuration, the cost of the mold increases when the circuit is changed, and there is also a work of fixing the bus bar to the insulating plate. There is a problem in that the use of a high cost.

[0006] Further, computerization has progressed even in the engine room, and the number of relays attached to an electric junction box arranged in the engine has increased. When the number of relays increases, there is a problem that a large space is required and the size of the electric connection box is large. When a large number of relays are arranged while saving space, there is a problem that heat generation occurs, and the relays are located close to the fuses, and are susceptible to heat generation on the input side of the fuses.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has been made to reduce the size of an electric junction box suitably used as a junction box for an engine room with a simple configuration and to reduce the use of bus bars as much as possible. And to reduce costs.

[0008]

In order to solve the above-mentioned problems, the present invention mainly provides an internal circuit of an electric connection box by providing a plurality of printed boards provided with conductors on one side, and using the plurality of printed boards. A hybrid in which a bus bar is disposed on the surface opposite to the conductor forming side as the printed circuit board, and a connection end formed by bending the bus bar is penetrated through an insulating plate and connected to the conductor by soldering. In the hybridized printed circuit board, a large current circuit serving as a power input side is formed by the bus bar, and an output side is provided by a conductor on the back side. The present invention provides an electric junction box having a medium / small current circuit.

As described above, the internal circuit of the electric junction box is formed on a printed board, and the printed board is a single-sided conductor,
By arranging a bus bar on the surface opposite to the conductor forming side, a large current circuit serving as a power input side can be formed by the bus bar,
Since the medium / small current circuit is formed of a conductor instead of a bus bar, the bus bar usage can be reduced. In addition, since the medium and small current circuits, which become complex branch circuit shapes on the output side, are formed by printed conductors, the required circuit shape can be easily achieved, and the thickness of the conductor must be changed in width. Thus, the required current amount can be easily obtained.

On one side of the hybrid printed circuit board on the side where the busbars are arranged, a plurality of rows of relay blocks having relays mounted in a row are provided at intervals.
Between the blocks, a fuse block in which the terminals connected to the fuses are provided in a row is provided, and a bus bar is arranged between the relay block and the fuse block,
This arrangement pattern is regularly repeated.

Even when a large number of relays need to be mounted, as described above, the relay blocks in which the relays are arranged side by side are arranged at intervals and the relays are distributed, so that heat can be radiated. it can. In addition, since the relay blocks are arranged at intervals, if fuse blocks are arranged between them, an efficient arrangement can be achieved without increasing the size of the printed circuit board. Further, when a bus bar is arranged between the relay block and the fuse block, there is a space between the relay block and the fuse block, and the bus bar can be used as a heat radiation space at this space. In this way, by employing the above arrangement, it is possible to mount a large number of relays while increasing heat dissipation without increasing the board area.

The connector connecting tab provided on the bus bar is arranged in parallel with one side of the substrate to form a connector block. The parallel direction of the tab of the connector block is parallel to the parallel direction of the press-connecting terminals for connecting the relay and the fuse. And the orthogonal direction.

When the connector connection portions are gathered on one side of the board as described above, the relay blocks and the fuse blocks can be arranged in the above-described manner, and the relay, the fuse, and the fuse can be arranged without increasing the area of the printed board. The connector connection portion can be efficiently arranged on one surface of one printed circuit board.

In the hybrid printed circuit board, the input side of the fuse, relay, and connector is connected to a bus bar having a large current, and the output side is connected to a conductor having a medium or small current. It is possible to prevent overheating even if the electric junction box is downsized.

Specifically, the electric junction box of the present invention is provided with two printed boards, which are stacked one above the other via an insulating plate, and one printed board is provided on one side with a conductor having a thickness for a large current. A busbar is fixed to the other surface, a relay is mounted and a fuse is mounted on the fixed side of the busbar, and a conductor having a thickness for small current is provided on one surface of the other printed circuit board, and an electronic device connected to the conductor is provided. Components are mounted, and the conductors of the two printed boards are connected by a jumper wire extending over one side of the board.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the electric junction box 10 of the embodiment is disposed in an engine room (X).
It is provided separately from the junction box 11 arranged on the indoor (Y) side.

The electrical connection box 10 on the engine room side is connected to a junction box 11 on the indoor side via a wire harness W / H, and various electric components mounted on the engine room side, that is, lamps on the head side. , Electrical components around the engine, electronic fuel injection control unit (EF
It is connected to an electronic control unit such as I) via a wire harness to supply power to these electrical components and perform on / off control. Further, a CAN bus composed of electronic components and conductors housed in the electric connection box 10 and a multiplex signal circuit for serial communication are connected to an electronic display device or the like mounted on an instrument panel in the vehicle compartment without passing through the junction box 11. , Directly, via a communication bus.

As shown in FIG. 2, the electric junction box 10 has two printed boards 13 and 14 stacked one above the other with an insulating plate 15 interposed in a lower case 12, and the upper and lower printed boards 13 and 14 are connected to each other. They are connected by jumper wires 16 arranged on one side. The lower case 12 is covered and locked by an upper case 17, and furthermore, as a waterproof measure, an upper cover 18 is covered and the upper cover 18 is locked by a lock to the lower case 12.

Each of the printed boards 13 and 14 is
A single-sided board configuration in which conductors 22 and 23 are provided only on one side of boards 20 and 21 made of a rigid insulating resin is assembled on the upper and lower surfaces of an insulating resin-made insulating plate 15 having no through-hole and integrated. I have.

The printed circuit board 13 to be assembled on the upper surface of the insulating plate 15 has a conductor 22 having a thickness of 70 μm printed on the lower surface of the substrate 20, and a thick bus bar 26 for a large current is mounted on the upper surface of the printed circuit board 13. It is a plate. A connection terminal 26a bent downward is provided on the bus bar 26 on the upper surface. The connection terminal 26a protrudes to the lower surface through a terminal hole 20a formed in the substrate 20 and is soldered to the conductor 22. The width of the conductor 22 is further changed according to the circuit to be formed.
The conductor 22 of the circuit C1 upstream on the power supply side is wide while the circuit C2 downstream on the load side connected to the load side is narrow. In order to connect the circuit C2 to one end of the jumper wire 16, the connection ends are arranged in parallel along one side of the substrate 20.

On the upper surface of the printed circuit board 13, a bus bar 26 and a relay 31 are fixed, and a terminal for connecting to a fuse 30 inserted into a fuse accommodating portion 17a provided in the upper case 17 is projected. That is, FIG.
As shown in (A) and (B), the bus bar 26 is provided with a press contact terminal portion 26 b bent upward, and a press contact terminal 29 welded to the conductor 22 on the lower surface is projected upward through the substrate 20. . Press-connecting terminals 2 of these busbars
A press-contact slot having an open end is provided between the press-contact terminal 6b and the press-contact terminal 29 on the conductor side so as to press-connect the terminal of the fuse 30.

The fuse 30 has an input terminal 30a fitted to the pressure contact terminal portion 26b and an output terminal 30b directly fitted to the pressure contact terminal 29 for fitting. The fuse 30 has a press contact terminal 29A on the upstream side of the conductor 22 and a press contact terminal on the downstream side. 29B. Some of the fuses 30 are of a multi-type having two output terminals 30b, and are configured to be connected to two press-contact terminals 29 on the conductor side. The press contact terminal 29 is connected to the upstream side of the conductor 22 connected to the relay 31 and is connected to the relay 31 after being protected by the fuse 30.

Further, as shown in FIG. 6, a relay 31 is mounted on the side of the printed circuit board 13 where the bus bar 26 and the fuse 30 are mounted. A plurality of terminals 31a of each relay 31 are connected to conductors 22 through terminal holes 20b of substrate 20.
The terminal 31a and the conductor 22 are connected by soldering. Among the above-mentioned relays 31, the relay 31 interposed in the starter and ignition circuits has a fuse function.

The upper case 17 is provided with a connector accommodating portion 17b together with the fuse accommodating portion 17a. The terminals of the connector 32 to be inserted into the connector accommodating portion 17b are connected to the tab provided on the bus bar 26 and the conductor 22. The board 20 is penetrated, and is configured to be male and female connected to a connector connection tab 33 formed of a vertical terminal board protruding upward. The tab of the bus bar is connected to the connector 32A of the electric wire terminal on the power supply side, and the connection terminal 33 is connected to the connector 32B of the electric wire terminal on the load side.
The conductor 22 to be welded to the connection terminal 33 is a load side circuit C2.

As described above, on the upper surface of the printed circuit board 13, the bus bar 26, the press-connecting terminal 29 for connecting the fuse, the mounted relay 31, and the tab 33 connected to the conductor 22 are arranged. And the configuration shown in FIG. That is, a relay block I in which a plurality of relays 31 are arranged in a row is provided in three rows at intervals, and a fuse block II in which press-contact terminals 29 are arranged in a row is arranged between these relay blocks I. I have. A bus bar block II in which a strip-shaped bus bar 26 is arranged between the relay block I and the fuse block II.
I. Further, the connector connection tab 33 is arranged in parallel with the relay and the fuse blocks I and II along a section of the substrate 20 in a direction orthogonal to the relay, and the connector block IV is formed.

The printed circuit board 14 assembled on the lower surface of the insulating plate 15 has a conductor 23 having a thickness of 35 μm for a small current printed on the lower surface of the substrate 21, and electronic components 35 (capacitors, transistors, diodes, etc.) 23 and mounted. Since the conductor 23 is connected to the jumper wire 16, the conductor 23 constituting each circuit is arranged in parallel with one side of the substrate 21. A multiplex communication circuit is constituted by the circuit of the electronic component 35 and the conductor 23.

An outer peripheral edge of an insulating plate 15 interposed between the printed circuit boards 13 and 14 has a peripheral wall 15a protruding on both upper and lower sides.
The upper printed circuit board 13 is fitted into the upper side of the peripheral wall 15a, and the lower printed circuit board 14 is fitted into the lower side of the peripheral wall 15a to be integrally assembled. Reinforcing ribs 15b are provided at required positions on the upper and lower surfaces of the insulating plate 15 so as to be in contact with the lower surface of the printed circuit board 13 and the upper surface of the printed circuit board 14.

The conductor 22 of the printed circuit board 13 and the conductor 23 of the printed circuit board 14 are connected via a number of jumper wires 16 extending over one side of the boards 20 and 21. Both ends of these jumper wires 16 are connected by soldering to the ends of the conductors 22 arranged in parallel to one side of the substrate 20 and the ends of the conductors 23 arranged in parallel to one side of the substrate 1. The ends of the conductors 22 connected to the jumper wires 16 are gathered on the side facing the connector block IV.

In the electric junction box 10 having the above structure, the connector 32A of the electric wire terminal connected to the power supply is accommodated in the connector accommodating portion 17a of the upper case 17, and is connected to the bus bar 26 on the printed circuit board 13. The bus bar 26 is connected to the input terminal 30a of the fuse 30, and the output terminal 30b of the fuse is connected to the circuit C1 of the conductor 22. The fuse 30 is connected to the circuit of the conductor 22 connected to the bus bar 26. The conductor 22 is connected to the relay 31 on the downstream side after being connected to the fuse 30, and the connection end of the conductor 22 is connected to the conductor 23 of the printed circuit board 14 via the jumper wire 16. The circuit branched through the conductor 23 and the circuit passing through the electronic component 35 connected to the conductor 23 are connected again to the jumper wire 16, connected to the circuit C 2 of the conductor 22 on the printed circuit board 13 side, and connected to the connection terminal 33.
Through the connector 32B of the load-side electric wire terminal.

[0030]

As is apparent from the above description, in the electrical junction box of the present invention, at least one of the printed circuit boards to be laminated is hybridized, and the bus bar is fixed to the surface opposite to the conductor forming side. Since only the large current circuit on the side is a bus bar and the medium / small current circuits are formed of conductors, the bus bar usage can be reduced, and the production cost can be greatly reduced. In addition, since the medium and small current circuits, which become complex branch circuit shapes on the output side, are formed by printed conductors, the required circuit shape can be easily achieved, and the thickness of the conductor must be changed in width. Thus, the required current amount can be easily obtained.

Further, a relay and a fuse are mounted on the busbar side of the hybrid printed circuit board.
Since these arrangements are devised to disperse the relay blocks, the heat generated by the relays can be quickly radiated, and the heating inside the electric connection box can be suppressed. Further, since the fuse blocks are arranged between the relay blocks to be distributed, the relays and the fuses can be efficiently arranged on a small printed circuit board in a space-efficient manner. further,
By arranging the bus bars between the relay block and the fuse block to provide a gap, the heat radiation effect can be further enhanced.

Further, in order to connect the conductors of a plurality of printed circuit boards, usually, a connector is mounted on the printed circuit board, and both ends of the electric wire are connected to the connector by terminals. In the present invention, both ends of the jumper wire are connected to the printed circuit board. Since it is connected to the conductor by soldering, it is not necessary to mount the connector on the printed circuit board and it is not necessary to attach the connection terminal to the end of the electric wire, and it is possible to reduce the number of parts and the number of assembly steps. As a result, costs can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall view of an automobile showing a mounting location of an electric junction box according to the present invention.

FIG. 2 is an exploded perspective view of the electric junction box of the present invention.

FIG. 3 is a perspective view showing a state in which two printed circuit boards housed in the electric connection box are connected.

FIG. 4A is a bottom view of a hybrid printed circuit board, and FIG. 4B is a bottom view of a printed circuit board on which electronic components are mounted.

FIG. 5A is a perspective view showing a state where a fuse is connected to a bus bar and a conductor, and FIG. 5B is a cross-sectional view showing a state where a fuse is connected to a conductor.

FIG. 6 is a cross-sectional view showing a state where a relay is mounted on one printed circuit board in the electric connection box.

FIG. 7 is a perspective view of a conventional electric junction box.

FIG. 8 is an exploded perspective view of a conventional electric junction box.

[Explanation of symbols]

 Reference Signs List 10 Electrical connection box for engine room 11 Interior junction box 12 Lower case 13, 14 Printed circuit board 15 Insulating plate 16 Jumper wire 17 Upper case 18 Upper cover 20, 21 Substrate 22, 23 Conductor 26 Bus bar 29 Pressure contact terminal 30 Fuse 31 Relay 32 ( 32A, 32B) Connector 33 Connection terminal 35 Electronic component I Relay block II Fuse block III Busbar block IV Connector block

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Nozaki 1-10-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi Inside the Auto Network Engineering Laboratory Co., Ltd. 7-10 Inside Auto Network Engineering Laboratory Co., Ltd. (72) Inventor Tsutomu Naito 1-14 Nishisuehiro-cho, Yokkaichi-shi, Mie F-term in Sumitomo Wiring Systems Co., Ltd. 5G361 BA01 BA07

Claims (3)

[Claims] 1. A main part of an internal circuit of an electric connection box is formed by providing a plurality of printed boards provided with conductors on one side, and laminating the plurality of printed boards. A bus bar is arranged on the opposite surface, and a connection end formed by bending the bus bar is penetrated through an insulating plate to be connected to the conductor by soldering, and an electronic component is mounted on the conductor forming side. In the hybrid printed circuit board, the bus bar forms a large current circuit on the power input side, and the conductor on the back side forms a medium / small current circuit on the output side. Electrical junction box. 2. A plurality of rows of relay blocks having relays mounted thereon in a row are provided on one side of the hybrid printed circuit board on the bus bar arrangement side, and terminals for connecting a fuse are provided between these relay blocks. 2. The fuse block according to claim 1, wherein a fuse block is provided in a row, and a bus bar is arranged between the relay block and the fuse block, and the arrangement pattern is regularly repeated. Electrical junction box. 3. A connector block provided on the bus bar is arranged in parallel with one side of a substrate to form a connector block, and the tabs of the connector block are arranged in parallel with the press-connecting terminals for connecting the relay and the fuse. The electrical junction box according to claim 2, wherein the direction is orthogonal to the parallel direction.